A simplified form of Motu developed as a trade language in the Papuan region, in the southeast of the main island of New Guinea, originally known as Police Motu, and today known as Hiri Motu. After Tok Pisin and English, Hiri Motu was at the time of independence the third most commonly spoken of the more than 800 languages of Papua New Guinea, although its use has been declining for some years, mainly in favour of Tok Pisin.
Motu is a typical Austronesian language in that it is heavily vowel-based. Every Motu syllable ends in a vowel sound — this may be preceded by a single consonant (there are no "consonant clusters"). Vowel sounds may be either "pure" (consisting of a single basic sound) or diphthong (consisting of more than one basic sound). There are only five "pure" vowel sounds (approximately those of Italian); Motu diphthongs are written (and pronounced) as combinations of two "pure" vowels. The diphthongs "oi" and "oe" (both approximately like the diphthong in the English word "boy"), ""ai" and "ae" (both approximately like the diphthong in the English word "high") and "ao" and "au" (both approximately like the diphthong in the English word "cow") are the only vowel sounds that present difficulties.
There are sixteen consonants. These are b, d, g, gw, h, k, kw, l, m, n, p, r, s, t, v, and the velar fricative (ɣ), usually written as ḡ. The letter "r" is an alveolar lateral flap or "flapped r"; its IPA symbol is (ɺ), and it is closer to "l" than the equivalent consonant in English. In practice, the letters "r" and "l" form a single phoneme to native speakers of Motu. There is no letter "f": When it occurs in loan words, it is usually represented as "p".